Crank disk



Nov. 25, 1930. L. ROBERTSON CRANK DISK Filed D80. 16, 1929 Patented Nov. 25, 1930 UNITED STATES rnonnivcn nonnn'rsoimor .TonEno; oHIo CRANK nrsx Application filed December is; i929. Serial n). 414,440. i

This invention relates to a crank disk adapted to be driven by a reciprocating piston and the object of thepresent construction is to facilitate starting from a dead center position. With this end in view, the crank disk,

which carries the wrist pin, has a lost motion connection with an adjacent disk secured to the shaft to be driven. The last mentioned disk is driven through the medium of equidistant dogs or tumblers which are so disposed with relation to the wrist pin as to at Y ford the most appropriate distribution of the load. v The invention will be more particularly de- 1 scribedin connectionwith the accompanying drawings, inwhich l Figure 1 is a side elevation'of'the crank disk and'the elements associated therewith, parts being broken away.

Figure 2 is a section takenon the line 2--2 of Figure 1. a

Figure 3 is a section takenon the line 33 of Figure 1. l Figure V4: is a perspective view of one of the tumblers. i

As illustrated in the drawings, the invention is associated with a driven shaft 5 to whichv a sleeve or hub 6 is secured by a set screw7 or other suitable means. A disk or 3.0 the hub 6 and is provided with curved ini wardly .inclinedjslots 9 adapted to receive equally spaced tumblers 10 which simultaneously engage the ends of the slots to drive the disk or wheel 8 and thereby rotate the shaft 5. The tumblers 10 are carried by a crank disk 11 which is mounted on an extension of the hub 6 and which is provided with a wrist piny12 of any suitable type adapted to be connected with a reciprocating piston by which it is driven. The disks 8 andll are oonnected'by a. number of rivets 13 which are long enough to permit a relative movement of one disk on the other without binding. One of the disks, as 8, isprovided with slots 14: to permit thisrelative movement. I

Each tumbler 10 is formed with a pin 15 which is journaled in the disk 11 and the tumblers may be held in the slots 9 by suitwheel 8 is integrally or otherwise secured to able retaining means such as an annular plate l 16 secured to thedisk Sby screws 17..

Thetumblers 10 are spaced at equal in tervals about the center of the. disk 11 and when the diskis drivenf'forwardly one pin 15 is slightly in advance of the wrist pinl2 while the end of the slot 9 is slightly in advance of the. center line through the wrist pin and the shaft 5. The elongated slots 9 permit a lost motion connection between the disks 8 and 11 which facilitates starting from a dead center position and the power which is transmitted from the disk 11 to the disk 8 is equally distributed tangentially about the center of theshaft 5. The con- .65 struction described makes it possible to start easily from a dead center position, the leverage is uniformly distributed and vibration.

is eliminated.

WVhile I have shown and described specifi- J9 cally the preferred form of the invention, it is to be understood that the inventionincludes all such modifications as may fall within the scope of the appended claims.

hat I claim is: i h 1. The combination with a rotatable shaft and a disk secured thereon, of a seconddisk coaxial with the first disk, a wrist pin see cured to the second disk, and a driving connection between the two disks comprising tumblers pinned to one disk, theother disk having slots receiving saidtumblers, the slots being longer than the tumblers in a circumferential direction to allow a lost motionbetween the disks.

2. The combination with a rotatable shaft and a disk secured thereon, of a second disk coaxial with the first disk, a wrist pin secured to the second disk, tumblers pivotally mounted on one disk, the other disk having slots receiving said tumblers, said slots having greater length circumferentially than the tumblers to permit a limited movement of one disk circumferentially on the other.

3. The combination with a rotatable shaft anda disk secured thereon, of a second disk coaxial with the first disk, a wrist pin secured to the second disk, and a driving connection between the two disks comprising plvot pins carried by one disk with tumblers extending forwardly therefrom adjacent one face of the disk and curved inwardly, the other disk having correspondingly shaped slots receiving said tumblers, said slots being longer than the tumblers to allow a lost 7 motion between the disks.

l. 'lhecombination with a rotatableshaft and a disk secured thereon, of a seconddisk coaxial with the first disk, a. wrist pin secured to the second disk, tumblers pivotally mounted on the face of one disk which is adjacent the other disk, said tumblers being curved forwardly and inwardly from their pivots, said other disk having slots receiv ing the tumblers but of greater length than the tumblers to permit a limited movement of one disk circumferentially on the other.

In testimony whereof I have hereunto signed my name to this specification.

LAURENCE ROBERTSON. 

